This invention relates to a plastic container and, more particularly, to a container including cylindrical container receptacle, a circular container lid and to closure elements at the rim of the container receptacle and at the periphery of the container lid for locking the lid to the receptacle in a fluid-tight fit.
Many proposals have been disclosed and utilized for effectuating a fluid-tight seal between a circular container lid and a cylindrical container body. U.S. Pat. No. 4,293,080 to Letica, for example, discloses a resealable, cylindrical plastic container assembly with a rim and lid interlock structure which provides an efficacious rim-to-lid seal. The rim of the container body or receptacle is formed with a cross-sectionally semi-circular annular bead, while the lid is provided at its periphery with a cross-sectionally circular groove for conformingly engaging the rim bead upon a snap-lock fit of the lid to the container receptacle. On its inner side, the generally cylindrical wall of the receptacle or container body is formed with a single annular shoulder in the form of a rounded edge which is conformingly engaged by a corresponding lip on the container lid in a closed state of the container assembly.
U.S Pat. No. 4,293,080 further discloses a plurality of outwardly extending annular reinforcing ribs disposed on an outer side of the cylindrical wall of the receptacle in a region about the rim of the receptacle or container body. In the region of the reinforcing ribs the container wall is formed with an annular indentation whereby the reinforcing ribs do not project substantially beyond the outer surface of the cylindrical container wall. The container wall is further provided with a plurality of circumferentially equispaced longitudinal reinforcing ribs disposed in the indentation of the cylindrical container wall, each longitudinal rib being contiguous with each of the annular reinforcing ribs.
Various means have also been suggested and utilized for strengthening plastic container lids. U.S. Pat. No. 4,210,258 to von Holdt for example, discloses a circular plastic container lid provided at its periphery with a substantially V-shaped annular channel portion provided in a channel or groove with a multiplicity of angularly equispaced radially extending reinforcing fins. That patent also discloses a plurality of circular wave-shaped corrugations at the center of the container lid. U.S. Pat. No. 4,117,950 to Allen shows a cross-sectionally arcuate container lid provided on an inside surface with a multiplicity of angularly equispaced reinforcing ribs extending from the periphery of the lid to substantially the center thereof. The ribs are in the form of elongate ridges.
An object of the present invention is to provide a plastic container assembly of the above-described type with improved closure elements for enhancing the locking of the container lid to the container body and for increasing the effectiveness of the container seal.
Another object of the present invention is to provide a container receptacle body of the above-mentioned type with an improved reinforcing structure at the mouth of the container body.
Yet another object of the present invention is to provide a plastic container lid of the above-mentioned type with an improved reinforcing structure for enhancing the strength of the container lid while preserving the flexibility needed for resealing and reopening the container.